Mortgage Servicing Rights and Related Liabilities - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Servicing Asset at Amortized Cost [Line Items]
Excess spread financing - fair value	$ 519		$ 768
Mortgage servicing rights financing - fair value	20		$ 10
Excess Spread Financing Repurchase, Purchase Price		$ 277
Forward MSRs Sold
Servicing Asset at Amortized Cost [Line Items]
UPB	20,723			$ 1,266
Forward MSRs Sold, Subservicing Retained
Servicing Asset at Amortized Cost [Line Items]
UPB	$ 19,692			$ 1,144